Plastic bags are steadily gaining acceptance where consumer goods of all types must be bundled up for transport away from the point of sale. These bags are used in many different types of retail settings to include grocery stores, department stores of all types, building supply stores and any other setting where a lightweight, strong, easy to dispense bag, is required. The advantages of plastic bags over kraft paper bags are numerous. They are lighter in weight, take up less room when folded, resist water, and may be fabricated with integral handles that provide for easy transport of the loaded bag. They are reusable as trash can liners or can be reused to carry other items. Thermoplastic bags are also recyclable.
One disadvantage of plastic bags is their lack of inherent rigidity and ease of closure. The result of this disadvantage is seen in the grocery bag application where it is not unusual for a fully loaded bag to be placed on a consumer's vehicle seat just before leaving with the purchase. As the vehicle turns, the bags typically fall over spilling their contents. The consumer is then faced with the time-consuming and inconvenient task of packing the bag a second time before it can be removed from the vehicle.
There are several disclosures relating to providing a closure for plastic bags or flexible bags of some type. One group of such disclosures addresses the problem by providing a separate closure means or device to secure the bag. U.S. Pat. No. 3,820,200 to Myers discloses a bag closure comprising a flat disc of resilient material provided with an I-shaped slit therein. The end of the bag to be closed is drawn through the slit which grips the bag tightly, achieving closure.
A similar approach is shown in U.S. Pat. No. 4,174,554 to Flantua which discloses a closure having a base portion and a tongue portion. This device is wrapped around the bunched together bag sides which are trapped between the base and tongue portions. Closure is achieved by pulling the tongue portion through an opening in the base portion and lockingly engaging neck areas of the tongue portion in corresponding areas of the tongue portion. Both these devices suffer the disadvantage of requiring the user to bear the expense and keep track of a number of small, easily lost pieces. Further, it is possible that during use sharp edges on these items could damage the bag precluding reuse of the bag. An additional disadvantage is that once the fully loaded bag has been picked up, the closure device could become very tightly jammed into place and, thus, very difficult to remove.
Another approach for providing a bag closure is disclosed in U.S. Pat. No. 3,186,626 to Shvetz, the invention of which employs tie-strip portions created by perforations formed into the top of the bag. When the perforated areas are pulled two tie-straps are separated from the bag and can be tied together to provide closure. The major disadvantage of this method is that the resulting knot is extremely difficult to loosen. The forces generated when a knotted plastic bag is picked up close the knot so tightly that destruction of the bag may be required in order to gain access to the contents.
This disadvantage is shared by the closure of U.S. Pat. No. 5,044,775 to Rutledge which utilizes plastic film tie elements which are welded to the end portion and adjacent to the top of the bag. When engaged, the tie element of that invention creates a tightly bunched neck area held secure by the tie element. Again, once this closure is engaged on a fully loaded bag, it is extremely difficult to disengage the closure without possibly damaging the bag.
U.S. Pat. No. 3,865,303 to Korn also discloses a pair of tieing strips anchored at one end of the bag described therein. The free ends of the tieing strips are insertable through openings provided in the bag walls. After insertion through the openings the strips are pulled to effect a constriction of the mouth of the bag and the free ends of the strips are tied together. Once any fully loaded bag, particularly a plastic bag, has been closed using a knot in the bag material, the resulting knot can be difficult, if not impossible, to open without rendering the bag unusable. Thus the ability to reuse the bag is lost.
U.S. Pat. No. 4,273,174 to Potter discloses a handbag having two integral strap-loops. The strap-loops can be folded one atop the other to effect a loose closure to the bag. Such an approach is not acceptable for loaded plastic bags because when similarly constructed handles of those bags are so engaged, the contents of the bag will spill out when the bag is tipped over.
As can be seen, the many attempts to provide a bag closure have disadvantages that render the bag difficult to open after closure, may damage the bag during opening after closure, or may require the extra cost and effort of a separate closure device. The present invention represents a significant advance because it avoids those disadvantages, providing a closure that is easy to use, secure and easy to reopen after closure permitting reuse of the bag. Moreover, for bags suspended from a bag dispensing rack, the strap of the present invention provides a convenient means to pull the lead bag open for loading.
It is also possible to use the bag of the present invention in a bag dispensing system utilizing a pack of unitized bags. U.S. Pat. Nos. 5,183,158 to Boyd et al. and 4,989,732 to Smith, the contents of which are incorporated herein by reference in their entirety, describe a pack of unitized bags which are releasably connected such that when one bag is pulled from the dispensing rack after loading, the next bag in the pack is pulled open. That releasable connection can also be achieved using the easy-open bag pack, method of forming and system disclosed in U.S. Pat. No. 5,507,713, the contents of which are incorporated herein by reference in their entirety. That application discloses a bag pack made up of bags that have been subjected to a corona discharge treatment. The corona treatment is sufficient to cause adjacently facing treated surfaces of adjacent bags within the bag pack to releasably fuse to each other upon a localized application of force using a novel upper and lower anvil means. These and other advantages and features of the invention will be readily apparent to one of ordinary skill in the art upon an examination of the specification and drawings herein.